Add support for the SME2 ADD. SUB, FADD and FSUB instructions.
SUB and FSUB have the same form as ADD and FADD, except that
ADD also has a 2-operand accumulating form.
The 64-bit ADD/SUB instructions require FEAT_SME_I16I64 and the
64-bit FADD/FSUB instructions require FEAT_SME_F64F64.
These are the first instructions to have tied register list
operands, as opposed to tied single registers.
The parse_operands change prevents unsuffixed Z registers (width==-1)
from being treated as though they had an Advanced SIMD-style suffix
(.4s etc.). It means that:
Error: expected element type rather than vector type at operand 2 -- `add za\.s\[w8,0\],{z0-z1}'
becomes:
Error: missing type suffix at operand 2 -- `add za\.s\[w8,0\],{z0-z1}'
SME2 adds lookup table instructions for quantisation. They use
a new lookup table register called ZT0.
LUTI2 takes an unsuffixed SVE vector index of the form Zn[<imm>],
which is the first time that this syntax has been used.
Implementation-wise, the main things to note here are:
- the WHILE* instructions have forms that return a pair of predicate
registers. This is the first time that we've had lists of predicate
registers, and they wrap around after register 15 rather than after
register 31.
- the predicate-as-counter WHILE* instructions have a fourth operand
that specifies the vector length. We can treat this as an enumeration,
except that immediate values aren't allowed.
- PEXT takes an unsuffixed predicate index of the form PN<n>[<imm>].
This is the first instance of a vector/predicate index having
no suffix.
SME2 adds LD1 and ST1 variants for lists of 2 and 4 registers.
The registers can be consecutive or strided. In the strided case,
2-register lists have a stride of 8, starting at register x0xxx.
4-register lists have a stride of 4, starting at register x00xx.
The instructions are predicated on a predicate-as-counter register in
the range pn8-pn15. Although we already had register fields with upper
bounds of 7 and 15, this is the first plain register operand to have a
nonzero lower bound. The patch uses the operand-specific data field
to record the minimum value, rather than having separate inserters
and extractors for each lower bound. This in turn required adding
an extra bit to the field.
SME2 defines new MOVA instructions for moving multiple registers
to and from ZA. As with SME, the instructions are also available
through MOV aliases.
One notable feature of these instructions (and many other SME2
instructions) is that some register lists must start at a multiple
of the list's size. The patch uses the general error "start register
out of range" when this constraint isn't met, rather than an error
specifically about multiples. This ensures that the error is
consistent between these simple consecutive lists and later
strided lists, for which the requirements aren't a simple multiple.
SME2 adds a new format for the existing SVE predicate registers:
predicates as counters rather than predicates as masks. In assembly
code, operands that interpret predicates as counters are written
pn<N> rather than p<N>.
This patch adds support for these registers and extends some
existing instructions to support them. Since the new forms
are just a programmer convenience, there's no need to make them
more restrictive than the earlier predicate-as-mask forms.
Some SME2 instructions operate on a range of consecutive ZA vectors.
This is indicated by syntax such as:
za[<Wv>, <imml>:<immh>]
Like with the earlier vgx2 and vgx4 support, we get better error
messages if the parser allows all ZA indices to have a range.
We can then reject invalid cases during constraint checking.
Many SME2 instructions operate on groups of 2 or 4 ZA vectors.
This is indicated by adding a "vgx2" or "vgx4" group size to the
ZA index. The group size is optional in assembly but preferred
for disassembly.
There is not a binary distinction between mnemonics that have
group sizes and mnemonics that don't, nor between mnemonics that
take vgx2 and mnemonics that take vgx4. We therefore get better
error messages if we allow any ZA index to have a group size
during parsing, and wait until constraint checking to reject
invalid sizes.
A quirk of the way errors are reported means that if an instruction
is wrong both in its qualifiers and its use of a group size, we'll
print suggested alternative instructions that also have an incorrect
group size. But that's a general property that also applies to
things like out-of-range immediates. It's also not obviously the
wrong thing to do. We need to be relatively confident that we're
looking at the right opcode before reporting detailed operand-specific
errors, so doing qualifier checking first seems resonable.
SME2 adds various new fields that are similar to
AARCH64_OPND_SME_ZA_array, but are distinguished by the size of
their offset fields. This patch adds _off4 to the name of the
field that we already have.
SME2 has instructions that accept strided register lists,
such as { z0.s, z4.s, z8.s, z12.s }. The purpose of this
patch is to extend binutils to support such lists.
The parsing code already had (unused) support for strides of 2.
The idea here is instead to accept all strides during parsing
and reject invalid strides during constraint checking.
The SME2 instructions that accept strided operands also have
non-strided forms. The errors about invalid strides therefore
take a bitmask of acceptable strides, which allows multiple
possibilities to be summed up in a single message.
I've tried to update all code that handles register lists.
Quite a lot of SME2 instructions have an opcode bit that selects
between 32-bit and 64-bit forms of an instruction, with the 32-bit
forms being part of base SME2 and with the 64-bit forms being part
of an optional extension. It's nevertheless useful to have a single
opcode entry for both forms since (a) that matches the ISA definition
and (b) it tends to improve error reporting.
This patch therefore adds a libopcodes function called
aarch64_cpu_supports_inst_p that tests whether the target
supports a particular instruction. In future it will depend
on internal libopcodes routines.
SVE register lists were classified as SVE_REG, since there had been
no particular reason to separate them out. However, some SME2
instructions have tied register list operands, and so we need to
distinguish registers and register lists when checking whether two
operands match.
Also, the register list operands used a general error message,
even though we already have a dedicated error code for register
lists that are the wrong length.
libopcodes currently reports out-of-range registers as a general
AARCH64_OPDE_OTHER_ERROR. However, this means that each register
range needs its own hard-coded string, which is a bit cumbersome
if the range is determined programmatically. This patch therefore
adds a dedicated error type for out-of-range errors.
SME2 has many instructions that take a list of SVE registers.
There are often multiple forms, with different forms taking
different numbers of registers.
This means that if, after a successful parse and qualifier match,
we find that the number of registers does not match the opcode entry,
the associated error should have a lower priority/severity than other
errors reported at the same stage. For example, if there are 2-register
and 4-register forms of an instruction, and if the assembly code uses
the 2-register form with an out-of-range value, the out-of-range value
error against the 2-register instruction should have a higher priority
than the "wrong number of registers" error against the 4-register
instruction.
This is tested by the main SME2 patches, but seemed worth splitting out.
This patch moves the range checks on ZA vector select offsets from
gas to libopcodes. Doing the checks there means that the error
messages contain the expected range. It also fits in better
with the error severity scheme, which becomes important later.
(This is because out-of-range indices are treated as more severe than
syntax errors, on the basis that parsing must have succeeded if we get
to the point of checking the completed opcode.)
The patch also adds a new check_za_access function for checking
ZA accesses. That's a bit over the top for one offset check, but the
function becomes more complex with later patches.
sme-9-illegal.s checked for an invalid .q suffix using:
psel p1, p15, p3.q[w15]
but this is doubly invalid because it misses the immediate part
of the index. The patch keeps that test but adds another with
a zero index, so that .q is the only thing wrong.
The aarch64-tbl.h change includes neatening up the backslash
positions.
A later patch moves the range checking for ZA vector select
offsets from gas to libopcodes. That in turn requires the
immediate field to be big enough to support all parsed values.
This shouldn't be a particularly size-sensitive structure,
so there should be no memory problems with doing this.
za_tile_vector is also used for indexing ZA as a whole, rather than
just for indexing tiles. The former is more common than the latter
in SME2, so this patch generalises the name to "indexed_za".
The patch also names the associated structure, so that later patches
can reuse it during parsing.
This patch makes all SME instructions use F_STRICT, so that qualifiers
have to be provided explicitly rather than being inferred from other
operands. The main change is to move the qualifier setting from the
operand-level decoders to the opcode level.
This is one step towards consolidating the ZA parsing code and
extending it to handle SME2.
Most extension flags are named after the associated architectural
FEAT_* flags, but sme-i64 and sme-f64 were exceptions. This patch
adds sme-i16i64 and sme-f64f64 aliases, but keeps the old names too
for compatibility.
Regenerating BPF target using the maintainer mode emits:
.../opcodes/bpf-opc.c:57:11: error: conversion from ‘long unsigned int’ to ‘unsigned int’ changes value from ‘18446744073709486335’ to ‘4294902015’ [-Werror=overflow]
57 | 64, 64, 0xffffffffffff00ff, { { F (F_IMM32) }, { F (F_OFFSET16) }, { F (F_SRCLE) }, { F (F_OP_CODE) }, { F (F_DSTLE) }, { F (F_OP_SRC) }, { F (F_OP_CLASS) }, { 0 } }
The use of a narrow size to handle the mask CGEN in instruction format
is causing this error. Additionally eBPF `call' instructions
constructed by expressions using symbols (BPF_PSEUDO_CALL) emits
annotations in `src' field of the instruction, used to identify BPF
target endianness.
cpu/
* bpf.cpu (define-call-insn): Remove `src' field from
instruction mask.
include/
*opcode/cge.h (CGEN_IFMT): Adjust mask bit width.
opcodes/
* bpf-opc.c: Regenerate.
The newer update-copyright.py fixes file encoding too, removing cr/lf
on binutils/bfdtest2.c and ld/testsuite/ld-cygwin/exe-export.exp, and
embedded cr in binutils/testsuite/binutils-all/ar.exp string match.
This commit adds 'Ssstateen' extension, which is a supervisor-visible view
of the 'Smstateen' extension. It means, this extension implements sstateen*
and hstateen* CSRs of the 'Smstateen' extension.
Note that 'Smstateen' extension itself is unchanged but due to
implementation simplicity, it is implemented so that 'Smstateen' implies
'Ssstateen' (just like 'M' implies 'Zmmul').
This is based on the latest version of RISC-V Profiles
(version 0.9-draft, Frozen):
<226b7f6430>
bfd/ChangeLog:
* elfxx-riscv.c (riscv_implicit_subsets): Update implication rules.
(riscv_supported_std_s_ext) Add 'Ssstateen' extension.
gas/ChangeLog:
* config/tc-riscv.c (enum riscv_csr_class): Rename
CSR_CLASS_SMSTATEEN_AND_H{,_32} to CSR_CLASS_SSSTATEEN_...
Add CSR_CLASS_SSSTATEEN.
(riscv_csr_address): Support new/renamed CSR classes.
* testsuite/gas/riscv/csr.s: Add 'Ssstateen' extension to comment.
* testsuite/gas/riscv/csr-version-1p9p1.l: Reflect changes to
error messages.
* testsuite/gas/riscv/csr-version-1p10.l: Likewise.
* testsuite/gas/riscv/csr-version-1p11.l: Likewise.
* testsuite/gas/riscv/csr-version-1p12.l: Likewise.
* testsuite/gas/riscv/ssstateen-csr.s: Test for 'Ssstateen' CSRs.
* testsuite/gas/riscv/ssstateen-csr.d: Likewise.
* testsuite/gas/riscv/smstateen-csr-s.d: Test to make sure that
supervisor/hypervisor part of 'Smstateen' CSRs are accessible from
'RV32IH_Smstateen', not just from 'RV32IH_Ssstateen' that is tested
in ssstateen-csr.d.
include/ChangeLog:
* opcode/riscv-opc.h: Update DECLARE_CSR declarations with
new CSR classes.
It has bothered me for a long time that we have disabled LSP (and SPE)
tests. Also the LSP test comment indicating there is something wrong
with get_powerpc_dialect. I don't think there is. Decoding of a VLE
instruction depends on whether the processor is in VLE mode (some
processors support both VLE and standard PPC) which we flag per
section with SHF_PPC_VLE for decoding when disassembling.
Background: Some versions of powerpc e200 have "Lightweight Signal
Processing" support, examples being e200z215 and e200z425. As far as
I can tell, LSP and SPE are mutually exclusive. This seems to be
borne out by insn encoding, for example LSP "zvaddih" and SPE "evaddw"
have the same encoding. So none of the processor descriptions in
ppc_opts ought to have both PPC_OPCODE_LSP and PPC_OPCODE_SPE/2, if we
want disassembly to work. I also could not find anything to suggest
that the LSP insns are enabled only in VLE mode, which means the LSP
insns should not be in vle_opcodes.
Fix all this by moving the LSP insns to their own table, and add a new
e200z2 cpu entry with LSP support, removing LSP from -me200z4 and from
-mvle. (Yes, I know, as I said above some of the e200z4 processors
have LSP. Others have SPE. It's hard to choose good options. Think
of z2 as meaning earlier, z4 as later.) Also add -mlsp to allow
adding the LSP insn set.
include/
* opcode/ppc.h (lsp_opcodes, lsp_num_opcodes): Declare.
(LSP_OP_TO_SEG): Define.
binutils/
* doc/binutils.texi: Update ppc docs.
gas/
* config/tc-ppc.c (ppc_setup_opcodes): Add lsp opcodes to ppc_hash.
* doc/c-ppc.texi: Document e200 and lsp.
* testsuite/gas/ppc/lsp-checks.d: Assemble with -me200z2.
* testsuite/gas/ppc/lsp.d: Likewise, disassembly too.
* testsuite/gas/ppc/ppc.exp: Don't xfail lsp test.
opcodes/
* ppc-dis.c (ppc_opts): Add e200z2 and lsp. Don't set
PPC_OPCODE_LSP for e200z4 or vle.
(ppc_parse_cpu): Mutually exclude LSP and SPE.
(LSP_OPCD_SEGS): Define.
(lsp_opcd_indices): New array.
(disassemble_init_powerpc): Init lsp_opcd_indices.
(lookup_lsp): New function.
(print_insn_powerpc): Call it.
* ppc-opc.c: Include libiberty.h for ARRAY_SIZE and use throughout.
(vle_opcodes): Move LSP opcodes to..
(lsp_opcodes): ..here, and sort.
(lsp_num_opcodes): New.
This is a part of small tidying (declare tables in riscv-opc.c).
include/ChangeLog:
* opcode/riscv.h (riscv_rm, riscv_pred_succ): Move declarations to
opcodes/riscv-opc.c. New non-static definitions.
opcodes/ChangeLog:
* riscv-opc.c (riscv_rm, riscv_pred_succ): Move from
include/opcode/riscv.h. Add description.
Because riscv_insn_length started to support instructions up to 176-bit,
we need to increase packet buffer size to 176-bit in size.
include/ChangeLog:
* opcode/riscv.h (RISCV_MAX_INSN_LEN): Max instruction length for
use in buffer size.
opcodes/ChangeLog:
* riscv-dis.c (print_insn_riscv): Increase buffer size for max
176-bit length instructions.
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadMemPair extension, a collection of T-Head specific
two-GP-register memory operations.
The 'th' prefix and the "XTheadMemPair" extension are documented in a PR
for the RISC-V toolchain conventions ([1]).
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadMemIdx extension, a collection of T-Head specific
GPR memory access instructions.
The 'th' prefix and the "XTheadMemIdx" extension are documented in a PR
for the RISC-V toolchain conventions ([1]).
In total XTheadCmo introduces the following 44 instructions
(BU,HU,WU only for loads (zero-extend instead of sign-extend)):
* {L,S}{D,W,WU,H,HU,B,BU}{IA,IB} rd, rs1, imm5, imm2
* {L,S}R{D,W,WU,H,HU,B,BU} rd, rs1, rs2, imm2
* {L,S}UR{D,W,WU,H,HU,B,BU} rd, rs1, rs2, imm2
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadFMemIdx extension, a collection of
T-Head-specific floating-point memory access instructions.
The 'th' prefix and the "XTheadFMemIdx" extension are documented
in a PR for the RISC-V toolchain conventions ([1]).
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadMac extension, a collection of
T-Head-specific multiply-accumulate instructions.
The 'th' prefix and the "XTheadMac" extension are documented
in a PR for the RISC-V toolchain conventions ([1]).
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadCondMov extension, a collection of
T-Head-specific conditional move instructions.
The 'th' prefix and the "XTheadCondMov" extension are documented
in a PR for the RISC-V toolchain conventions ([1]).
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XThead{Ba,Bb,Bs} extensions, a collection of
T-Head-specific bitmanipulation instructions.
The 'th' prefix and the "XThead{Ba,Bb,Bs}" extension are documented
in a PR for the RISC-V toolchain conventions ([1]).
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
This patch introduces support for arbitrary signed or unsigned immediate
encoding formats. The formats have the form "XsN@S" and "XuN@S" with N
being the number of bits and S the LSB position.
For example an immediate field of 5 bytes that encodes a signed value
and is stored in the bits 24-20 of the instruction word can use the
format specifier "Xs5@20".
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadSync extension, a collection of
T-Head-specific multi-processor synchronization instructions.
The 'th' prefix and the "XTheadSync" extension are documented in a PR
for the RISC-V toolchain conventions ([1]).
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
T-Head has a range of vendor-specific instructions.
Therefore it makes sense to group them into smaller chunks
in form of vendor extensions.
This patch adds the XTheadCmo extension, a collection of T-Head specific
cache management operations.
The 'th' prefix and the "XTheadCmo" extension are documented in a PR
for the RISC-V toolchain conventions ([1]).
In total XTheadCmo introduces the following 21 instructions:
* DCACHE.{C,CI,I}ALL
* DCACHE.{C,CI,I}{PA,VA,SW} rs1
* DCACHE.C{PAL1,VAL1} rs1
* ICACHE.I{ALL,ALLS}
* ICACHE.I{PA,VA} rs1
* L2CACHE.{C,CI,I}ALL
Contrary to Zicbom, the XTheadCmo instructions don't have a constant
displacement, therefore we have a different syntax for the arguments.
To clarify this is intended behaviour, there is a set of negative test
for Zicbom-style arguments in x-thead-cmo-fail.s.
[1] https://github.com/riscv-non-isa/riscv-toolchain-conventions/pull/19
v2:
- Add missing DECLARE_INSN() list
- Fix ordering
Co-developed-by: Lifang Xia <lifang_xia@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
The -mfuture and -Mfuture options which are used for adding potential
new ISA instructions were not documented. They also lacked a bitmask
so new instructions could not be enabled by those options. Fixed.
binutils/
* doc/binutils.texi: Document -Mfuture.
gas/
* config/tc-ppc.c: Document -mfuture
* doc/c-ppc.texi: Likewise.
include/
* opcode/ppc.h (PPC_OPCODE_FUTURE): Define.
opcodes/
* ppc-dis.c (ppc_opts) <future>: Use it.
* ppc-opc.c (FUTURE): Define.
Three-part patch set from Tsukasa OI to support zmmul in assembler.
The 'Zmmul' is a RISC-V extension consisting of only multiply instructions
(a subset of 'M' which has multiply and divide instructions).
bfd/
* elfxx-riscv.c (riscv_implicit_subsets): Add 'Zmmul' implied by 'M'.
(riscv_supported_std_z_ext): Add 'Zmmul' extension.
(riscv_multi_subset_supports): Add handling for new instruction class.
gas/
* testsuite/gas/riscv/attribute-09.d: Updated implicit 'Zmmul' by 'M'.
* testsuite/gas/riscv/option-arch-02.d: Likewise.
* testsuite/gas/riscv/m-ext.s: New test.
* testsuite/gas/riscv/m-ext-32.d: New test (RV32).
* testsuite/gas/riscv/m-ext-64.d: New test (RV64).
* testsuite/gas/riscv/zmmul-32.d: New expected output.
* testsuite/gas/riscv/zmmul-64.d: Likewise.
* testsuite/gas/riscv/m-ext-fail-xlen-32.d: New test (failure
by using RV64-only instructions in RV32).
* testsuite/gas/riscv/m-ext-fail-xlen-32.l: Likewise.
* testsuite/gas/riscv/m-ext-fail-zmmul-32.d: New failure test
(RV32 + Zmmul but with no M).
* testsuite/gas/riscv/m-ext-fail-zmmul-32.l: Likewise.
* testsuite/gas/riscv/m-ext-fail-zmmul-64.d: New failure test
(RV64 + Zmmul but with no M).
* testsuite/gas/riscv/m-ext-fail-zmmul-64.l: Likewise.
* testsuite/gas/riscv/m-ext-fail-noarch-64.d: New failure test
(no Zmmul or M).
* testsuite/gas/riscv/m-ext-fail-noarch-64.l: Likewise.
include/
* opcode/riscv.h (enum riscv_insn_class): Added INSN_CLASS_ZMMUL.
ld/
* testsuite/ld-riscv-elf/attr-merge-arch-01.d: We don't care zmmul in
these testcases, so just replaced m by a.
* testsuite/ld-riscv-elf/attr-merge-arch-01a.s: Likewise.
* testsuite/ld-riscv-elf/attr-merge-arch-01b.s: Likewise.
* testsuite/ld-riscv-elf/attr-merge-arch-02.d: Likewise.
* testsuite/ld-riscv-elf/attr-merge-arch-02a.s: Likewise.
* testsuite/ld-riscv-elf/attr-merge-arch-03.d: Likewise.
* testsuite/ld-riscv-elf/attr-merge-arch-03a.s: Likewise.
* testsuite/ld-riscv-elf/attr-merge-user-ext-01.d: Likewise.
* testsuite/ld-riscv-elf/attr-merge-user-ext-rv32i2p1_a2p0.s: Renamed.
* testsuite/ld-riscv-elf/attr-merge-user-ext-rv32i2p1_a2p1.s: Renamed.
opcodes/
* riscv-opc.c (riscv_opcodes): Updated multiply instructions to zmmul.
svstep and svshape instructions subtract 1 before encoding some of the
operands. Obviously zero is not supported for these operands. Whilst
PPC_OPERAND_PLUS1 fits perfectly to mark that maximal value should be
incremented, there is no flag which marks the fact that zero values are
not allowed. This patch adds a new flag, PPC_OPERAND_NONZERO, for this
purpose.
This patch adds support for LibreSOC machine and SVP64 extension flag
for PowerPC architecture. SV (Simple-V) is a strict RISC-paradigm
Scalable Vector Extension for the Power ISA. SVP64 is the 64-bit
Prefixed instruction format implementing SV. Funded by NLnet through EU
Grants No: 825310 and 825322, SV is in DRAFT form and is to be publicly
submitted via the OpenPOWER Foundation ISA Working Group via the
newly-created External RFC Process.
For more details, visit https://libre-soc.org.
This commit enables disassembler styling for AArch64. After this
commit it is possible to have objdump style AArch64 disassembler
output (using --disassembler-color option). Once the required GDB
patches are merged, GDB will also style the disassembler output.
The changes to support styling are mostly split between two files
opcodes/aarch64-dis.c and opcodes/aarch64-opc.c.
The entry point for the AArch64 disassembler can be found in
aarch64-dis.c, this file handles printing the instruction mnemonics,
and assembler directives (e.g. '.byte', '.word', etc). Some operands,
mostly relating to assembler directives are also printed from this
file. This commit changes all of this to pass through suitable
styling information.
However, for most "normal" instructions, the instruction operands are
printed using a two step process. From aarch64-dis.c, in the
print_operands function, the function aarch64_print_operand is called,
this function is in aarch64-opc.c, and converts an instruction operand
into a string. Then, back in print_operands (aarch64-dis.c), the
operand string is printed.
Unfortunately, the string returned by aarch64_print_operand can be
quite complex, it will include syntax elements, like '[' and ']', in
addition to register names and immediate values. In some cases, a
single operand will expand into what will appear (to the user) as
multiple operands separated with a ','.
This makes the task of styling more complex, all these different
components need to by styled differently, so we need to get the
styling information out of aarch64_print_operand in some way.
The solution that I propose here is similar to the solution that I
used for the i386 disassembler.
Currently, aarch64_print_operand uses snprintf to write the operand
text into a buffer provided by the caller.
What I propose is that we pass an extra argument to the
aarch64_print_operand function, this argument will be a structure, the
structure contains a callback function and some state.
When aarch64_print_operand needs to format part of its output this can
be done by using the callback function within the new structure, this
callback returns a string with special embedded markers that indicate
which mode should be used for each piece of text. Back in
aarch64-dis.c we can spot these special style markers and use this to
split the disassembler output up and apply the correct style to each
piece.
To make aarch64-opc.c clearer a series of new static functions have
been added, e.g. 'style_reg', 'style_imm', etc. Each of these
functions formats a piece of text in a different style, 'register' and
'immediate' in this case.
Here's an example taken from aarch64-opc.c of the new functions in
use:
snprintf (buf, size, "[%s, %s]!",
style_reg (styler, base),
style_imm (styler, "#%d", opnd->addr.offset.imm));
The aarch64_print_operand function is also called from the assembler
to aid in printing diagnostic messages. Right now I have no plans to
add styling to the assembler output, and so, the callback function
used in the assembler ignores the styling information and just returns
an plain string.
I've used the source files in gas/testsuite/gas/aarch64/ for testing,
and have manually gone through and checked that the styling looks
reasonable, however, I'm not an AArch64 expert, so it is possible that
the odd piece is styled incorrectly. Please point out any mistakes
I've made.
With objdump disassembler color turned off, there should be no change
in the output after this commit.
